This disclosure relates to a method for producing and using catalysts for the production of bisphenols, and in particular to a method for producing catalysts which contain attached poly-sulfur mercaptan promoters, and using these catalysts in the production of bisphenol-A, and its derivatives.
Typical bisphenols, such as 4,4xe2x80x2-isopropylidenediphenol, e.g., bisphenol-A (BPA), are widely employed as monomers in the manufacture of polymeric materials, such as engineering thermoplastics. For example, BPA is a principal monomer used in the manufacture of polycarbonate. Bisphenols are generally prepared by the electrophilic addition of aldehydes, or ketones such as acetone, to aromatic hydroxy compounds such as phenol, in the presence of an acidic catalyst compositions. These types of reactions are also referred to as acid catalyzed condensation reactions. Commercially, sulfonated polystyrene resin cross-linked with divinylbenzene, e.g., PS-DVB, is typically used as a solid acid component of the catalyst composition. Reaction promoters can also be employed as part of a catalyst composition to improve the reaction rate, and selectivity, of the desired condensation reaction; in the case of BPA, the desired selectivity is for the para-para isomer (pp-BPA). Promoters can be present as unattached molecules in the bulk reaction matrix, e.g., xe2x80x9cbulk-promotersxe2x80x9d, or can be attached to the resin through ionic linkages, e.g., xe2x80x9cattached-promotersxe2x80x9d. A useful class of promoter is the mercaptans, specifically thiols, e.g., organosulfur compounds which are derivatives of hydrogen sulfide. Typical mercaptan promoters contain only a single sulfur atom, and result in catalyst compositions that catalyze bisphenol formation with poor isomer selectivity; in the case of BPA, the undesired selectivity if for the ortho-para isomer (op-BPA). Consequently, a long felt yet unsatisfied need exists for new and improved catalyst compositions, and a method to produce them, which are selective in the production of bisphenols. Herein, a method to produce catalyst compositions comprising poly-sulfur mercaptan promoters is disclosed. The use of poly-sulfur mercaptan promoters results in catalyst compositions that are highly selective in the formation of bisphenols. 
In one embodiment, the present disclosure pertains to a method for producing a catalyst composition which catalyzes the formation of bisphenols from aromatic hydroxy compounds and carbonyl containing compounds, said method comprising the step of attaching a poly-sulfur mercaptan promoter component to a solid acid support component comprising a protic acid functionality, said poly-sulfur mercaptan promoter component having the following structure (I), 
wherein R1 is a functionality selected from the group consisting of a positively charged ammonium functionality, a positively charged guanidinium functionality, a positively charged phosphonium functionality, and a neutral amine;
wherein a is between about 0 and about 11;
wherein b is between about 1 and about 11;
wherein c is between about 1 and about 11;
wherein d is between about 1 and about 5;
wherein X is a linking functionality which is one member selected from the group consisting of a linear aliphatic chain comprising between about 1 and about 11 carbon atoms, a cyclic aliphatic ring comprising at least 5 carbon atoms, a cyclic aromatic ring comprising at least 6 carbon atoms, a cyclic aliphatic heterocycle comprising at least 3 carbon atoms, and a cyclic aromatic heterocycle comprising at least 3 carbon atoms;
wherein Y is a linking functionality which is one member selected from the group consisting of a linear aliphatic chain comprising between about 1 and about 11 carbon atoms, a cyclic aliphatic ring comprising at least 5 carbon atoms, a cyclic aromatic ring comprising at least 6 carbon atoms, a cyclic aliphatic heterocycle comprising at least 3 carbon atoms, and a cyclic aromatic heterocycle comprising at least 3 carbon atoms; and
wherein R2 is one member selected from the group consisting of a hydrogen, a tertiary aliphatic functionality, an ester functionality, a carbonate functionality, and a benzyl functionality which is attached via the benzylic methylene carbon.
In another embodiment, the present disclosure relates to a method for forming bisphenols, comprising the step of reacting an aromatic hydroxy compound with a carbonyl containing compound in the presence of a catalyst composition, said catalyst composition comprising a solid acid component and a poly-sulfur mercaptan promoter component having the following structure (I), 
wherein R1 is a functionality selected from the group consisting of a positively charged ammonium functionality, a positively charged guanidinium functionality, a positively charged phosphonium functionality, and a neutral amine;
wherein a is between about 0 and about 11;
wherein b is between about 1 and about 11;
wherein c is between about 1 and about 11;
wherein d is between about 1 and about 5;
wherein X is a linking functionality which is one member selected from the group consisting of a linear aliphatic chain comprising between about 1 and about 11 carbon atoms, a cyclic aliphatic ring comprising at least 5 carbon atoms, a cyclic aromatic ring comprising at least 6 carbon atoms, a cyclic aliphatic heterocycle comprising at least 3 carbon atoms, and a cyclic aromatic heterocycle comprising at least 3 carbon atoms;
wherein Y is a linking functionality which is one member selected from the group consisting of a linear aliphatic chain comprising between about 1 and about 11 carbon atoms, a cyclic aliphatic ring comprising at least 5 carbon atoms, a cyclic aromatic ring comprising at least 6 carbon atoms, a cyclic aliphatic heterocycle comprising at least 3 carbon atoms, and a cyclic aromatic heterocycle comprising at least 3 carbon atoms; and
wherein R2 is one member selected from the group consisting of a hydrogen, a tertiary aliphatic functionality, an ester functionality, a carbonate functionality, and a benzyl functionality which is attached via the benzylic methylene carbon.